Unify otel's HostMetrics, IIS, and MSSQL structs under the otel.Recei…

…ver interface.

confgenerator/confgenerator.go

@@ -40,9 +40,7 @@ func (uc *UnifiedConfig) GenerateOtelConfig(hostInfo *host.InfoStat) (string, er
 	metrics := uc.Metrics
 	userAgent, _ := getUserAgent("Google-Cloud-Ops-Agent-Metrics", hostInfo)
 	versionLabel, _ := getVersionLabel("google-cloud-ops-agent-metrics")
-	hostMetricsList := []*otel.HostMetrics{}
-	mssqlList := []*otel.MSSQL{}
-	iisList := []*otel.IIS{}
+	receiverList := []otel.Receiver{}
 	stackdriverList := []*otel.Stackdriver{}
 	serviceList := []*otel.Service{}
 	excludeMetricsList := []*otel.ExcludeMetrics{}
@@ -62,7 +60,7 @@ func (uc *UnifiedConfig) GenerateOtelConfig(hostInfo *host.InfoStat) (string, er
 		}
 
 		var err error
-		hostMetricsList, mssqlList, iisList, receiverNameMap, err = generateOtelReceivers(metrics.Receivers, metrics.Service.Pipelines)
+		receiverList, receiverNameMap, err = generateOtelReceivers(metrics.Receivers, metrics.Service.Pipelines)
 		if err != nil {
 			return "", err
 		}
@@ -80,9 +78,7 @@ func (uc *UnifiedConfig) GenerateOtelConfig(hostInfo *host.InfoStat) (string, er
 		}
 	}
 	otelConfig, err := otel.Config{
-		HostMetrics:    hostMetricsList,
-		IIS:            iisList,
-		MSSQL:          mssqlList,
+		Receivers:      receiverList,
 		ExcludeMetrics: excludeMetricsList,
 		Stackdriver:    stackdriverList,
 		Service:        serviceList,
@@ -97,10 +93,10 @@ func (uc *UnifiedConfig) GenerateOtelConfig(hostInfo *host.InfoStat) (string, er
 	return otelConfig, nil
 }
 
-func generateOtelReceivers(receivers map[string]MetricsReceiver, pipelines map[string]*MetricsPipeline) ([]*otel.HostMetrics, []*otel.MSSQL, []*otel.IIS, map[string]string, error) {
-	hostMetricsList := []*otel.HostMetrics{}
-	mssqlList := []*otel.MSSQL{}
-	iisList := []*otel.IIS{}
+func generateOtelReceivers(receivers map[string]MetricsReceiver, pipelines map[string]*MetricsPipeline) ([]otel.Receiver, map[string]string, error) {
+	hostMetricsList := []otel.Receiver{}
+	mssqlList := []otel.Receiver{}
+	iisList := []otel.Receiver{}
 	receiverNameMap := make(map[string]string)
 	for _, pID := range sortedKeys(pipelines) {
 		p := pipelines[pID]
@@ -138,7 +134,11 @@ func generateOtelReceivers(receivers map[string]MetricsReceiver, pipelines map[s
 			}
 		}
 	}
-	return hostMetricsList, mssqlList, iisList, receiverNameMap, nil
+	receiverList := []otel.Receiver{}
+	receiverList = append(receiverList, hostMetricsList...)
+	receiverList = append(receiverList, mssqlList...)
+	receiverList = append(receiverList, iisList...)
+	return receiverList, receiverNameMap, nil
 }
 
 func generateOtelExporters(exporters map[string]MetricsExporter, pipelines map[string]*MetricsPipeline) ([]*otel.Stackdriver, map[string]string, error) {

confgenerator/otel/conf.go

@@ -23,15 +23,9 @@ import (
 var confTemplate = template.Must(template.New("conf").Parse(
 	`receivers:
   {{template "agentreceiver" .}}
-{{- range .HostMetrics}}
-  {{template "hostmetrics" .}}
-{{- end}}
-{{- range .MSSQL}}
-  {{template "mssql" .}}
-{{- end}}
-{{- range .IIS}}
-  {{template "iis" .}}
-{{- end}}
+{{- range .Receivers}}
+  {{.Generate -}}
+{{end}}
 processors:
   {{template "defaultprocessor" .}}
 {{- range .ExcludeMetrics}}
@@ -587,21 +581,75 @@ service:
           - action: toggle_scalar_data_type
 {{- end -}}`))
 
+type Receiver interface {
+	Generate() (string, error)
+	pipelineID() string
+	defaultProcessors() []string
+}
+
 type HostMetrics struct {
 	HostMetricsID      string
 	CollectionInterval string
 }
 
+func (r *HostMetrics) Generate() (string, error) {
+	var builder strings.Builder
+	if err := confTemplate.ExecuteTemplate(&builder, "hostmetrics", r); err != nil {
+		return "", err
+	}
+	return builder.String(), nil
+}
+
+func (r *HostMetrics) defaultProcessors() []string {
+	return []string{"agentmetrics/system", "filter/system", "metricstransform/system", "resourcedetection"}
+}
+
+func (r *HostMetrics) pipelineID() string {
+	return "system"
+}
+
 type IIS struct {
 	IISID              string
 	CollectionInterval string
 }
 
+func (r *IIS) Generate() (string, error) {
+	var builder strings.Builder
+	if err := confTemplate.ExecuteTemplate(&builder, "iis", r); err != nil {
+		return "", err
+	}
+	return builder.String(), nil
+}
+
+func (r *IIS) defaultProcessors() []string {
+	return []string{"metricstransform/iis", "resourcedetection"}
+}
+
+func (r *IIS) pipelineID() string {
+	return "iis"
+}
+
 type MSSQL struct {
 	MSSQLID            string
 	CollectionInterval string
 }
 
+func (r *MSSQL) Generate() (string, error) {
+	var builder strings.Builder
+	if err := confTemplate.ExecuteTemplate(&builder, "mssql", r); err != nil {
+		return "", err
+	}
+	return builder.String(), nil
+}
+
+func (r *MSSQL) defaultProcessors() []string {
+	return []string{"metricstransform/mssql", "resourcedetection"}
+}
+
+func (r *MSSQL) pipelineID() string {
+	return "mssql"
+}
+
 type ExcludeMetrics struct {
 	ExcludeMetricsID string
 	MetricNames      []string
@@ -621,9 +669,7 @@ type Service struct {
 }
 
 type Config struct {
-	HostMetrics    []*HostMetrics
-	IIS            []*IIS
-	MSSQL          []*MSSQL
+	Receivers      []Receiver
 	ExcludeMetrics []*ExcludeMetrics
 	Stackdriver    []*Stackdriver
 	Service        []*Service

confgenerator/otel/conf_test.go

@@ -141,27 +141,27 @@ func TestSection(t *testing.T) {
 func TestGenerateOtelConfig(t *testing.T) {
 	tests := []struct {
 		name            string
-		hostMetricsList []*HostMetrics
-		iisList         []*IIS
-		mssqlList       []*MSSQL
+		receiverList    []Receiver
 		stackdriverList []*Stackdriver
 		serviceList     []*Service
 		want            string
 	}{
 		{
 			name: "default system metrics config",
-			hostMetricsList: []*HostMetrics{{
-				HostMetricsID:      "hostmetrics/hostmetrics",
-				CollectionInterval: "60s",
-			}},
-			iisList: []*IIS{{
-				IISID:              "windowsperfcounters/iis_iis",
-				CollectionInterval: "60s",
-			}},
-			mssqlList: []*MSSQL{{
-				MSSQLID:            "windowsperfcounters/mssql_mssql",
-				CollectionInterval: "60s",
-			}},
+			receiverList: []Receiver{
+				&HostMetrics{
+					HostMetricsID:      "hostmetrics/hostmetrics",
+					CollectionInterval: "60s",
+				},
+				&MSSQL{
+					MSSQLID:            "windowsperfcounters/mssql_mssql",
+					CollectionInterval: "60s",
+				},
+				&IIS{
+					IISID:              "windowsperfcounters/iis_iis",
+					CollectionInterval: "60s",
+				},
+			},
 			stackdriverList: []*Stackdriver{{
 				StackdriverID: "googlecloud/google",
 				UserAgent:     "$IGNORED_VALUE",
@@ -715,9 +715,7 @@ service:
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			got, err := Config{
-				HostMetrics: tc.hostMetricsList,
-				IIS:         tc.iisList,
-				MSSQL:       tc.mssqlList,
+				Receivers:   tc.receiverList,
 				Stackdriver: tc.stackdriverList,
 				Service:     tc.serviceList,